Luke Tryl has been announced as the new director of the New Schools Network.
Mr Tryl is currently head of corporate strategy at Ofsted, and before that worked as special adviser for Nicky Morgan when she was education secretary.
The appointment marks an end to a period of uncertainty for the NSN, which supports people to set up free schools.
Toby Young, the journalist and founder of the West London Free School, resigned as director of the charity following the controversy over his short-lived appointment to the board of the new Office for Students, which he left after concerns were raised about crude comments he made on social media.
Former free school headteacher Mark Lehain took over as interim director, but stood down in October.
Commenting on his appointment, Mr Tryl said: "Throughout my time in government and as a trustee of a free school multi-academy trust, I've seen first-hand the life-transforming impact that free schools are having on young people right across the country.
'Real momentum' in free schools movement
"That's why I'm delighted to be joining the New Schools Network to help build on that record of success and to support more parents, teachers, charities and community groups in their drive to ensure that every single child receives the world-class education they deserve."
David Ross, the NSN's chair, said: "We are delighted to welcome Luke to the New Schools Network.
"He has a wealth of experience across the educational sector and will be instrumental in developing NSN over the coming years.
"With over 440 free schools now open and 262 more in the pipeline, there continues to be real momentum in the free schools movement and we're excited to see Luke take up this post and continue our work to drive school improvement across the country."
Amanda Spielman, Ofsted's chief inspector, said: "Luke has done an enormous amount for Ofsted in his two years here, leading our strategy work and the strengthening of our research function, and playing a large part in the development of the new education inspection framework.
"We have all very much enjoyed working with him and wish him every success at the New Schools Network, where I know he will excel, as he has here."